Function pyoxidizerlib::project_building::find_pyoxidizer_config_file_env

pub fn find_pyoxidizer_config_file_env(
    logger: &Logger, 
    start_dir: &Path
) -> Option<PathBuf>

Find a PyOxidizer configuration file from walking the filesystem or an environment variable override.

We first honor the PYOXIDIZER_CONFIG environment variable. This allows explicit control over an exact file to use.

We then try scanning ancestor directories of OUT_DIR. This variable is populated by Cargo to contain the output directory for build artifacts for this crate. The assumption here is that this code is running from the pyembed build script or as pyoxidizer. In the latter, OUT_DIR should not be set. In the former, the crate that is building pyembed likely has a config file and OUT_DIR is in that crate. This doesn’t always hold. But until Cargo starts passing an environment variable defining the path of the main or calling manifest being built, it is the best we can do.

If none of the above find a config file, we fall back to traversing ancestors of start_dir.